Elevator roller guide

ABSTRACT

A guiding device ( 30 ) for an elevator system ( 20 ) facilitates guiding a cab ( 22 ) along guide rails ( 24 ). The guiding device ( 30 ) includes a roller mount ( 34 ) that supports rollers ( 36 ) such that the rollers remain a fixed distance from each other. A biasing member ( 44 ) urges the mount ( 34 ) in a direction that maintains contact between the guide rail ( 24 ) and the rollers ( 36 ) and facilitates centering the guiding device ( 30 ) and the cab ( 22 ) relative to the guide rails ( 24 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to elevator systems. More particularly,this invention relates to a roller guide device for use in an elevatorsystem.

2. Description of the Prior Art

Elevator systems are well known. A cab typically is guided within ahoistway along guide rails that extend vertically within the hoistway.Various configurations of guiding arrangements have been developed toprovide smooth movement of the cab along the guide rails.

Typical guiding arrangements include rollers that roll alongcorresponding surfaces on a nose of the guide rail. One challenge facingdesigners of such devices is to provide for appropriate tolerances inthe spacing of the rollers so that smooth movement of the cab isachieved by appropriate cooperation between the rollers and the guiderail nose surfaces. Manufacturing tolerances and variations in thesurfaces on the guide rails make it difficult to have one roller guidedevice design be readily incorporated into a variety of elevatorsystems.

Another concern is maintaining contact between the guide rail and therollers under the elevator operating conditions. For example, the cabmay shift during travel because of weight shifts within the cab or otherforces tending to move the cab laterally.

One approach is shown in U.S. Pat. No. 6,345,698. In that patent, tworollers are independently spring mounted such that the rollers arebiased into engagement with the nose of a guide rail.

There is always a need for an improved arrangement. This inventionprovides a unique, self-centering roller guide arrangement.

SUMMARY OF THE INVENTION

In general terms, this invention is a roller guide device that maintainsappropriate contact between rollers and a guide rail and centers theroller guide, which facilitates centering the elevator cab.

One example roller device designed according to this invention includesa base. A roller mount is moveably secured to the base. Rollers aresupported on the mount with their axes a fixed distance from each other.A biasing member urges the mount into a position where the rollersengage a guide rail without changing the distance between the rollers toestablish appropriate roller and guide rail contact and to center theroller guide, which facilitates centering the elevator cab.

In one example, the roller mount is pivotally supported on the base sothat it moves about a pivot axis responsive to the bias of the biasingmember and responsive to changes in the lateral alignment of the cabwith the guide rail.

In one example, the roller mount also supports low friction materialinserts that slide along a corresponding surface on the nose of theguide rail. In another example, a secondary roller is supported by thebase and oriented generally perpendicular to the primary rollers so thatthe secondary roller follows along a corresponding surface on the noseof the guide rail. Each of the two examples provides lateral carpositioning in two directions.

The various features and advantages of this invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an elevator system including a guidedevice designed according to this invention.

FIG. 2 is a perspective illustration of an example embodiment of aroller guide device designed according to this invention.

FIG. 3 is a partial, cross-sectional view taken along the lines 3-3 inFIG. 2.

FIG. 4A schematically illustrates selected portions of the embodiment ofFIG. 2 in a first operating condition.

FIG. 4B schematically illustrates the selected components of FIG. 4Aunder different operating conditions.

FIG. 5 is a planar view taken from the top of FIG. 2.

FIG. 6 is a perspective illustration of another example embodiment of aroller guide device designed according to this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 schematically illustrates an elevator system 20. An elevator cab22 moves along guide rails 24 in a known manner. The guide rails 24 aresecured within a hoistway, for example, in a conventional manner so thata nose portion 26 of the T-shaped guide rails 24 faces toward theelevator cab 22.

At least one self-centering roller guide device 30 is supported on thecab to cooperate with each of the guide rails 24. More particularly, theroller guide device 30 includes rollers that roll along the oppositelyfacing surfaces of the nose portion 26 of the guide rails 24.

FIG. 2 illustrates one example roller guide device designed according tothis invention. The guide device 30 includes a rigid base 32, which maybe made from steel, for example. The base 32 is adapted to be mounted ina fixed position relative to the cab 22.

A roller mount 34 is moveably supported by the base 32 such that theroller mount 34 can move relative to the base 32. A set of rollers 36are supported on the roller mount 34 using a conventional shaft andbearing arrangement, for example. The rollers 36 rotate about axes 38that are generally perpendicular to the longitudinal axis of thecorresponding guide rail 24. The axes 38 are generally parallel to theoppositely facing surfaces on the nose portion 26 along which therollers 36 travel as the cab 22 moves up or down. The rollers 36 remaina fixed distance from each other because their axes 38 are fixedrelative to the mount 34.

In the illustrated example, the roller mount 34 is supported on a shaft42 such that the roller mount 34 can be pivoted relative to the base 32.A biasing member 44 biases the roller mount 34 as shown by the arrow 46to adjust the position of the roller mount 34 relative to the base 32.

As the roller mount 34 pivots about the shaft 42 responsive to the forceof the biasing member 44, the roller axes 38 move according to the arrow46. By rotating or pivoting the roller mount 34 in a clockwise direction(according to the drawing) for example, the roller axes 38 both movetoward a vertical center of the device 30 (according to the drawing)and, therefore, into engagement with the oppositely facing surfaces ofthe guide rail nose portion 26.

In the illustrated example, a single biasing member urges both rollersinto engagement with the rail. Therefore, a single adjustmentaccomplishes the desired ride quality associated with the guiding device30. The biasing member 44 in the illustrated example includes a threadedadjusting member 47 having a first end 48 and a second end 49. In theillustrated example, the second end 49 is similar to the head of a screwso that the threaded member 47 may be rotated using a conventionalscrewdriver, for example. The first end 48 in the illustrated exampleincludes a nut that is rotationally secured by a support surface 50 onthe roller mount 34. Rotating the threaded member 47 changes thedistance between the support surface 50 and the second end 49 of thethreaded member 47 and compresses a spring 52 a selected amount. Thespring 52 provides the biasing force to urge the rollers 36 against therail noise 26.

The threaded adjustment member 47 allows for manually compressing thespring 52 to draw the roller mount 34 into a position that facilitatesinstalling the roller guide device 30 in an elevator system. Once thecab and roller guide are in a desired position, the adjusting member 47can be used to adjust the tension or bias of the spring 52, whichfacilitates maintaining a desired amount of contact between the rollers36 and the oppositely facing surfaces of the nose portion 26 to achievea desired ride quality (i.e., smoothness).

The example biasing member 44 includes the spring 52 that urges thesupport surface 50 away from a support surface 54 on the base 32. Thespring 52 allows for resiliently maintaining the roller mount 34 in adesired position. A resilient arrangement provides certain advantages sothat there is some give or play in the position of the rollers 36relative to the guide rail nose 26. Moreover, as will be describedbelow, the biasing member urges the guide device 30 into a centered,aligned position relative to the guide rail.

In the illustrated example, locking nuts 56 secure the threaded member47 into a desired position, which maintains a desired tension or biasingforce on the roller mount 34. This typically corresponds to both rollers36 engaging the oppositely facing surfaces of the nose portion 26 on thecorresponding guide rail 24 under normal operating conditions.

The biasing member of the roller guide device 30 serves to maintain therollers 36 in proper engagement with the guide rail 24. Additionally,the biasing member urges the roller guide device 30 into a centeredposition relative to the guide rail. The manner in which the rollerguide is associated with the elevator cab 22 facilitates centering thecab 22 relative to the guide rails 24.

FIG. 4A schematically shows the rollers 36 in engagement with oppositefacing surfaces of the nose portion 26 of the guide rail 24. The roller36A contacts one side of the nose portion 26 while the roller 36Bcontacts the other side. The force of the biasing member 44 urges therollers 36A and 36B according to the arrow 46. This figure schematicallyillustrates a position of the rollers and the roller guide device undernormal operating conditions.

Under some circumstances, the elevator cab 22 is subjected to forcesthat tend to cause lateral movement of the cab relative to the guiderails 24. A force arrow 60 schematically illustrates a lateral forcecausing lateral movement of the elevator cab 22. Such movement urges theroller mount 34 against the bias of the biasing member 44 asschematically shown by the arrow 62. In this situation, the roller 36Aremains in contact with one side of the nose 26. The rotation of theroller mount 34 relative to the base 32 against the biasing force of thebiasing member 44 results in the roller 36B no longer contacting thecorresponding side of the nose portion 26.

A significant advantage to the inventive arrangement is that the forceof the biasing member 44 tends to urge the rollers 36A and 36B back intothe position of FIG. 4A to realign the roller guide device 30 relativeto the guide rail nose portion 26 so that the roller guide 30 isreturned to a centered position. Such movement also urges the cab 22back into an aligned, centered position relative to the guide rails.

Those skilled in the art who have the benefit of this description willbe able to select an appropriate biasing member having a sufficienturging force to obtain a desired amount of centered alignment of theroller guide device and elevator cab to meet the needs of theirparticular situation. In one example, the biasing member urges the cabback into a centered position once the laterally shifting forcedissipates. In another example, the urging force of the biasing memberis strong enough to resist lateral movement of the cab up to a chosenforce limit.

The action of the biasing member 44 operates to center the cab in atleast one lateral direction (i.e., fore and aft). Some exampleembodiments of this invention also include a centering feature thatfacilitates maintaining a lateral alignment of the cab in aperpendicular, lateral direction (i.e., side-to-side).

As can be appreciated from FIGS. 2 and 3, the example roller mount 34supports inserts 64 made from a commercially available, low-frictionmaterial such as plastic or Teflon. The inserts 64 are adapted to slidealong an end face on the nose portion 26 of a corresponding guide rail24. Contact between the inserts 64 and the guide rail nose 26 limitslateral movement in that direction (i.e., side-to-side).

The example roller mount 34 also includes brace members 66 that operateto limit the amount of counterclockwise (according to the drawings)rotation of the roller mount 34. The brace members 66 will engage theopposite surfaces of the nose portion 26 in the event, for example, thatthe elevator cab tends to move laterally beyond the anticipatedresistance provided by the biasing member 44. The inventive rollerdevice limits the amount of horizontal or lateral movement of the cab bythe resistance provided by the biasing member 44 and, under somecircumstances, engagement between the brace members 62 and the guiderail surfaces.

Another feature of the inventive arrangement is having support surfaces54 at the top and bottom of the base 32 extending generallyperpendicular to a substantial portion of the body of the base 32. One(the top according to the drawings) of the support services 54 includesan opening 68 that receives at least a portion of the adjuster 47 andallows for adjustments to be made conveniently from above the rollerguide device. Both support surfaces 54 preferably include a recess 70that is adapted to engage the guide rail in the event of relativelylarge amounts of lateral cab movement, for example. Under somecircumstances, lateral shifting of the cab 22 may urge the roller mount34 into such a position (such as that shown in FIG. 4B, for example)that the side surfaces of the recesses 70 contact a correspondingsurface on the nose portion 26 of the guide rail. Under suchcircumstances, the recesses 70 operate as a sliding type guide as knownin the art. In one example, the surfaces of the recesses 70 preferablydo not engage the nose portion 26 except under extreme operatingconditions.

As known in the art, sliding guides typically require lubrication alongthe nose portion 26 of the guide rails. The inventive arrangementincluding the rollers 36 does not require lubrication on the guide railsurface and, therefore, the sliding, guiding operation of the recesses70 preferably is used only on a very limited basis. In one example, thesliding, guiding function of the recesses 70 is a back up in the eventthat one of the rollers 36 should fail to operate as intended.

As can be appreciated from FIG. 5, sufficient lateral movement of thecab (i.e., from right to left in FIG. 5) would result in contact betweenthe nose portion 26 and one of the side surfaces of the recesses 70. Theinventive arrangement not only facilitates movement of the elevator cabalong the guide rail but also provides control of forces perpendicularto the axes of the guide rails.

Another embodiment is shown in FIG. 6, which is particularly adapted forhigher speed elevator operation. In this example, the base 32 includesan opening 80 through which a roller 82 at least partially protrudes.The base 32 supports the roller 82, so that it rotates about an axis 84that is generally perpendicular to the axes 38 of the rollers 36. Theroller 82 is adapted to roll along the terminal surface of the noseportion 26 as the cab moves. The roller mount 34′ in this example has adifferent configuration compared to that shown in the example of FIGS. 2and 3 to accommodate the roller 82. A variety of configurations arewithin the scope of this invention.

The roller 82 facilitates preventing lateral movement of the rollerguide device 30, and therefore the cab 22, in a direction that isperpendicular to that accommodated by the biasing member 44. The exampleembodiment of FIG. 6, therefore facilitates maintaining a centered cabalignment in four lateral directions (i.e., fore, aft, left and right).

The inventive arrangement provides a self-centering, economical rollerguide arrangement that also provides cab-centering features. One exampleembodiment of this invention presents cost savings and better systemperformance because it utilizes a roller guide arrangement that is aseconomical to manufacture as a typical slide-guide arrangement. Theinventive arrangement also provides cost savings because it requiresfewer parts, easier installation and simpler adjustment.

The preceding description is exemplary rather than limiting in nature.Variations and modifications to the disclosed examples may becomeapparent to those skilled in the art that do not necessarily depart fromthe essence of this invention. The scope of legal protection given tothis invention can only be determined by studying the following claims.

1. A device for guiding movement of an elevator cab along a guide rail,comprising: a base; a roller mount moveably supported by the base andpivotable about an axis; a plurality of rollers supported on the rollermount, the rollers having roller axes that are a fixed distance apartand parallel to the axis; a biasing member that urges the roller mountto pivot about the axis in a direction that urges one of the rollersagainst a first side of the guide rail and another one of the rollersagainst an oppositely facing second side of the guide rail, the biasingmember is operative to center the base relative to the guide rail; andat least one other member that is operative to resist movement of thebase in a direction parallel to the roller axes, the at least one othermember being rigidly secured against movement along the directionparallel to the roller axes, the at least one other member remainingfixed relative to the base along the direction parallel to the rolleraxes, the at least one other member comprising at least one of an insertsupported on the roller mount or a roller supported by the base andhaving an axis of rotation that is perpendicular to axes of theplurality of rollers.
 2. The device of claim 1, wherein the biasingmember urges the roller mount to rotate in one direction about the axis.3. The device of claim 1, wherein the biasing member comprises a springthat resiliently maintains the roller mount in a selected position. 4.The device of claim 1, wherein the roller mount includes a brace memberextending generally parallel to axes of the plurality of rollers andthat is adapted to engage a surface on the guide rail responsive tolateral movement of the base relative to the guide rail.
 5. The deviceof claim 1, wherein the base includes a guide surface adapted to engagea surface on a guide rail responsive to lateral movement of the baserelative to the guide rail.
 6. The device of claim 1, wherein thebiasing member comprises a spring and a threaded member for adjusting adistance between a support surface on the roller mount and a supportsurface on the base to thereby selectively adjust a tension on thespring.
 7. An elevator system, comprising: at least one guide rail; acab that is adapted to move along the guide rail; and a guiding deviceassociated with the cab, the guiding device including a base, a rollermount supported by the base and pivotable about an axis, a plurality ofrollers supported on the roller mount, the rollers having roller axesthat are a fixed distance apart and parallel to the axis, wherein thefixed distance between the roller axes establishes a distance betweenthe rollers that is greater than a thickness of the guide rail betweenthe first and second sides of the guide rails such that no more than oneof the rollers contacts a corresponding one of the sides of the guiderail when the roller axes are along a line that is generallyperpendicular to the first and second sides of the guide rail; and abiasing member that urges the roller mount to pivot about the axis in adirection that urges one of the rollers against a first side of theguide rail and another one of the rollers against an oppositely facingsecond side of the guide rail.
 8. The system of claim 7, wherein thebiasing member comprises a spring.
 9. The system of claim 7, wherein thebiasing member resists lateral movement of the base relative to theguide rail in a direction that is generally perpendicular to the firstside of the guide rail.
 10. The system of claim 9, including at leastone other member adapted to resist movement of the base in a directionperpendicular to the direction of lateral movement resisted by thebiasing member.
 11. The system of claim 10, wherein the at least oneother member comprises a low friction insert.
 12. The system of claim10, wherein the at least one other member comprises a roller.
 13. Thesystem of claim 7, comprising a shaft supported by the base, and whereinthe roller mount is supported by the shaft.
 14. The system of claim 13,wherein the shaft is parallel to the roller axes.
 15. The system ofclaim 7, comprising an adjuster associated with the biasing member foradjusting a bias of the biasing member on the roller mount.
 16. Thesystem of claim 7, wherein the biasing member urges the roller mount ina direction that urges the roller axes toward a vertical center of thebase.
 17. The system of claim 7, comprising at least one brace memberassociated with the roller mount for selectively contacting the guiderail and limiting a corresponding movement of the roller mount relativeto the guide rail.
 18. The system of claim 17, wherein the at least onebrace member is fixed to the roller mount.
 19. The system of claim 7,comprising at least one support surface that remains fixed relative tothe base for selectively contacting the guide rail and limiting acorresponding movement of the base relative to the guide rail.
 20. Thesystem of claim 19, wherein the support surface is near at least one endof the base and the support surface comprises a recess configured suchthat a side of the recess contacts the guide rail responsive to thecorresponding movement of the base relative to the guide rail.